Infectious diseases as cause and as risk factor of cerebrovascular ischemia

Cerebrovascular ischemia can be caused by infectious diseases which involve cerebral arteries or the heart, including infectious endocarditis, bacterial and fungal meningitis, neurosyphilis, neuroborreliosis, herpes tester, the acquired immunodeficiency syndrome, cat scratch disease and other rare infectious diseases. Presently, there is increasing evidence that infection in general and mainly respiratory infection is a risk factor for ischemic stroke. Case reports and smaller case series reported an association of cerebrovascular ischemia and recent infection in children and younger adults. Two case control studies from Helsinki (54 patients under the age of 50) and from Heidelberg (197 patients aged 80 or less) identified recent infection as an important risk factor for ischemic stroke. Febrile, bacterial and respiratory infections were most important in this respect. In the study from Heidelberg, the neurological deficit was more severe and cardioembolism was more frequent in infection-associated stroke than in stroke without preceding infection. This review summarizes the association of infectious diseases and cerebrovascular ischemia and discusses potential pathogenetic mechanisms linking both diseases.